The githzerai are a hard humanlike people who dwell in the plane of Limbo. The githzerai highly regard their lightning reflexes and iron will; both traits are essential for survival in the tumult of Limbo. Creative thought, however, is not.

Githzerai are taller and thinner than humans, with sharp features, long faces, and eyes of gray and yellow. Severe and serious, the githzerai tend toward somberness both in dress and personality. As a rule, githzerai are close-mouthed, keep their own counsel, and trust few outside their own kind. Many githzerai are monks; however, sorcercers, rogues, and multiclass githzerai (called zerths) are also indispensable members of a monastery.

[Source: Manual of the Planes by Jeff Grubb, Bruce R. Cordell, and David Noonan. Published by Wizards of the Coast. p.175-176. Also PS3E, Chapter 2, p.24]